Is there information about the numbers of Carter vs. Marvel-Schebler carburetors used on the 35’s and F-40’s?
I do have part numbers, both MF and manufacturers, for the carburetors used on these models if that is what you are asking. As to the number of tractors equipped with Carter verses Marvel Schebler carburetors, I do not believe that information was ever collected or noted.
From an observational standpoint I can tell you that while both Marvel Schebler and Carter carburetors were used on the TO-30, I have seen very few TO-30’s with Carter carburetors.
When it comes to early TO-35, F-40 and MH-50 models it seems the number is almost equal.
When it comes to later TO-35 models, MF-35 and MF-50 models most if not all appear to be Marvel Schebler carburetors.
The Carter carburetors seem to be more finicky to adjust, but once adjusted perform well. The Carter carburetors, being constructed of cast zinc are not as durable as the cast iron Marvel Schebler’s.
Parts for the Carter’s are almost impossible to find today which is one of the main reasons I suggest replacing them with the Marvel-Schebler versions.
Ferguson and Massey Ferguson manuals have very little information on rebuilding the Carter’s so you have to rely on service bulletins published by Carter. I have spoken to dealers that were not aware the Carter service bulletins were available, and either repaired and rebuilt the Carters without instructions or referred to shop manuals for Farmall and International Harvestor tractors which used similar carburetors on the A, Super A, B, C, and Super C.
I do know that early TO-35 tractors had carburetor problems as many were improperly assembled by Continental with the wrong model Marvel Schebler carburetor. There is a factor service bulletin directing dealers to check early TO-35 tractors and replace the Marvel Schebler carburetors as required. I believe the problem was these TO-35’s were assembled with TO-30 carburetors which will work but not provide optimum performance.